如何排序使用CollectionViewSource一个LongListSelector

问题描述

我有一个 LongListSelector 当前正在填充图片来自 IsolatedStorage 。我希望能够通过日期升序或降序排序这些。我一直在引用寻求帮助。出于某种原因，我有麻烦绑定的ItemsSource 我的 LongListSelector 到 CollectionViewSource 来实现排序功能。

PictureRepository.cs（从 IsolatedStorage 应用程序启动时）

 ＃区域常数
 
公共常量字符串IsolatedStoragePath =图片; 
 
 #endregion 
 
＃区域属性
 
公众的ObservableCollection<图片和GT;图片
 {
获得; 
私人集; 
} 
 
 #endregion 
 
＃地区Singleton模式
 
私人PictureRepository（）
 {
 LoadAllPicturesFromIsolatedStorage（ ）; 
} 
 
公共静态只读PictureRepository实例=新PictureRepository（）; 
 
 #endregion 
 
 ///<总结> 
 ///保存到本地存储
 ///这个方法有两个参数：捕获图像实例，并在独立存储
图片文件夹的名称///< /总结> ; 
 ///< PARAM NAME =capturedPicture>< /参数> 
 ///< PARAM NAME =目录>< /参数> 
公共无效SaveToLocalStorage（CapturedPicture capturedPicture，串目录）
 {
 //调用IsolatedStorageFile.GetUserStoreForApplication得到一个独立的存储文件
 VAR isoFile = IsolatedStorageFile.GetUserStoreForApplication（）; 
 //调用位于公用IsolatedStorageFileExtensions类IsolatedStorageFile.EnsureDirectory扩展方法，以确认照片文件夹存在。 
 isoFile.EnsureDirectory（目录）; 
 
 //合并图像文件夹，并捕获图像文件名，并使用该路径来创建新文件
串文件路径= Path.Combine（目录，capturedPicture.FileName）;使用
（VAR FILESTREAM = isoFile.CreateFile（文件路径））
 {
使用（VAR作家=新的BinaryWriter（FILESTREAM））
 {
 capturedPicture.Serialize（作家）; 
} 
} 
} 
 
 ///<总结> 
 ///要加载所有保存的图片，并将它们添加到图片列表页
 ///< /总结> 
公共CapturedPicture LoadFromLocalStorage（字符串文件名，目录字符串）
 {
 //要打开文件，添加到IsolatedStorageFile.GetUserStoreForApplication 
 VAR isoFile = IsolatedStorageFile.GetUserStoreForApplication（）的调用; 
 
 //结合的目录和文件名
字符串文件路径= Path.Combine（目录，文件名）; 
 //使用路径通过IsolatedStorageFile.OpenFile方法
使用（VAR FILESTREAM = isoFile.OpenFile（文件路径，FileMode.Open，FileAccess.Read））$打开从独立存储的图片文件b $ b {
 //使用反序列化CapturedPicture例如
（VAR读者=新BinaryReader（FILESTREAM））
 {
变种capturedPicture =新CapturedPicture创建一个BinaryReader实例（） ; 
 //创建一个名为CapturedPicture.Deserialize反序列化捕获的图像，并返回它的类型CapturedPicture的新实例
 capturedPicture.Deserialize（读卡器）; 
返回capturedPicture; 
} 
} 
} 
 
 ///<总结> 
 ///要加载在启动时
 ///<的所有图片; /总结> 
私人无效LoadAllPicturesFromIsolatedStorage（）
 {
 //添加调用IsolatedStorageFile.GetUserStoreForApplication打开一个独立的存储文件
 VAR isoFile = IsolatedStorageFile.GetUserStoreForApplication（）; 
 //调用位于公用IsolatedStorageFileExtensions类IsolatedStorageFile.EnsureDirectory扩展方法，以确认照片文件夹存在
 isoFile.EnsureDirectory（IsolatedStoragePath）; 
 
 //调用使用的图片目录，* .JPG的IsolatedStorageFile.GetFileNames作为过滤器来获取所有保存的图片
 VAR pictureFiles = isoFile.GetFileNames（Path.Combine（IsolatedStoragePath，* .JPG））; 
 
变种照片=新的List<图片和GT;（）; 
 
 //通过迭代列表中的所有图片文件，每个使用先前创建
的foreach（在pictureFiles PictureFile的变种）
的LoadFromLocalStorage加载{
变种图片= LoadFromLocalStorage（PictureFile的，IsolatedStoragePath）; 
 pictures.Add（图片）; 
} 
 
图片=新的ObservableCollection<图片和GT;（pictures.OrderBy（X => x.DateTaken））; 
} 
  





App.xaml.cs

 公共静态PictureRepository PictureList 
 {
得到
 {
返回PictureRepository.Instance; 
} 
} 
  





MainPage.xaml中

 <电话：LongListSelector X：NAME =最近的保证金=0,0,0,72
 LayoutMode =网格GridCellSize = 108,108
的SelectionChanged =recent_SelectionChanged> 
  

MainPage.xaml.cs中

 ＃地区的字段
 
公共System.Windows.Data.CollectionViewSource来源{搞定;组; } 
 
 #endregion 
 
保护覆盖无效的OnNavigatedTo（NavigationEventArgs E）
 {
 //Recent.ItemsSource = App.PictureList.Pictures; //工作，未分类的
 
来源=新System.Windows.Data.CollectionViewSource（）; 
 Source.Source = App.PictureList.Pictures; //不工作
 //需要某种形式的铸造到IList的LongListSelector？ 
 Recent.ItemsSource = Source.View作为IList的< ??>（）; 
 
如果（Settings.AscendingSort.Value）
 {
 //Recent.ItemsSource = PictureRepository.Instance.Pictures.OrderBy（X => x.DateTaken）; 
 //Recent.ItemsSource = App.PictureList.Pictures.OrderBy（X => x.DateTaken）; 
 Source.SortDescriptions.Clear（）; 
 Source.SortDescriptions.Add（新SortDescription（日期，ListSortDirection.Ascending））; 
} 
，否则
 {
 //Recent.ItemsSource = PictureRepository.Instance.Pictures.OrderByDescending（X => x.DateTaken）; 
 //Recent.ItemsSource = App.PictureList.Pictures.OrderByDescending（X => x.DateTaken）; 
 Source.SortDescriptions.Clear（）; 
 Source.SortDescriptions.Add（新SortDescription（日期，ListSortDirection.Descending））; 
 
} 
} 
  

解决方案

是最好，最简单的解决方案。稍微改变了我的实现，但它的伟大工程。

I have a LongListSelector that is currently being populated with images from IsolatedStorage. I would like be able to sort these by date in ascending or descending order. I have been referencing http://babaandthepigman.wordpress.com/2011/07/03/wp7-collectionviewsource-sorting-a-listbox/ for assistance. For some reason, I have having trouble binding the ItemsSource of my LongListSelector to the CollectionViewSource to implement the sort feature.

PictureRepository.cs (to load the pictures from IsolatedStorage when application starts)

#region Constants

    public const string IsolatedStoragePath = "Pictures";

    #endregion

    #region Properties

    public ObservableCollection<Picture> Pictures
    {
        get;
        private set;
    }

    #endregion

    #region Singleton Pattern

    private PictureRepository()
    {
        LoadAllPicturesFromIsolatedStorage();
    }

    public static readonly PictureRepository Instance = new PictureRepository();

    #endregion

    /// <summary>        
    /// Saves to local storage
    /// This method gets two parameters: the captured picture instance and the name of the pictures folder in the isolated storage
    /// </summary>
    /// <param name="capturedPicture"></param>
    /// <param name="directory"></param>
    public void SaveToLocalStorage(CapturedPicture capturedPicture, string directory)
    {
        //call IsolatedStorageFile.GetUserStoreForApplication to get an isolated storage file
        var isoFile = IsolatedStorageFile.GetUserStoreForApplication();
        //Call the IsolatedStorageFile.EnsureDirectory extension method located in the Common IsolatedStorageFileExtensions class to confirm that the pictures folder exists.
        isoFile.EnsureDirectory(directory);

        //Combine the pictures folder and captured picture file name and use this path to create a new file 
        string filePath = Path.Combine(directory, capturedPicture.FileName);
        using (var fileStream = isoFile.CreateFile(filePath))
        {
            using (var writer = new BinaryWriter(fileStream))
            {
                capturedPicture.Serialize(writer);
            }
        }
    }

    /// <summary>
    /// To load all saved pictures and add them to the pictures list page
    /// </summary>
    public CapturedPicture LoadFromLocalStorage(string fileName, string directory)
    {
        //To open the file, add a call to the IsolatedStorageFile.GetUserStoreForApplication
        var isoFile = IsolatedStorageFile.GetUserStoreForApplication();

        //Combine the directory and file name
        string filePath = Path.Combine(directory, fileName);
        //use the path to open the picture file from the isolated storage by using the IsolatedStorageFile.OpenFile method
        using (var fileStream = isoFile.OpenFile(filePath, FileMode.Open, FileAccess.Read))
        {
            //create a BinaryReader instance for deserializing the CapturedPicture instance
            using (var reader = new BinaryReader(fileStream))
            {
                var capturedPicture = new CapturedPicture();
                //create a new instance of the type CapturedPicture called CapturedPicture.Deserialize to deserialize the captured picture and return it
                capturedPicture.Deserialize(reader);
                return capturedPicture;
            }
        }
    }

    /// <summary>
    /// To load all the pictures at start time
    /// </summary>
    private void LoadAllPicturesFromIsolatedStorage()
    {
        //add call to the IsolatedStorageFile.GetUserStoreForApplication to open an isolated storage file
        var isoFile = IsolatedStorageFile.GetUserStoreForApplication();
        //Call the IsolatedStorageFile.EnsureDirectory extension method located in the Common IsolatedStorageFileExtensions class to confirm that the pictures folder exists
        isoFile.EnsureDirectory(IsolatedStoragePath);

        //Call the IsolatedStorageFile.GetFileNames using the pictures directory and *.jpg as a filter to get all saved pictures
        var pictureFiles = isoFile.GetFileNames(Path.Combine(IsolatedStoragePath, "*.jpg"));

        var pictures = new List<Picture>();

        //Iterate through all the picture files in the list and load each using the LoadFromLocalStorage you created earlier
        foreach (var pictureFile in pictureFiles)
        {
            var picture = LoadFromLocalStorage(pictureFile, IsolatedStoragePath);
            pictures.Add(picture);
        }

        Pictures = new ObservableCollection<Picture>(pictures.OrderBy(x => x.DateTaken));
    }

App.xaml.cs

public static PictureRepository PictureList
    {
        get
        {
            return PictureRepository.Instance;
        }
    }

MainPage.xaml

<phone:LongListSelector x:Name="Recent" Margin="0,0,0,72"
                                    LayoutMode="Grid" GridCellSize="108,108" 
                                    SelectionChanged="recent_SelectionChanged">

MainPage.xaml.cs

#region Fields

    public System.Windows.Data.CollectionViewSource Source { get; set; }

#endregion

protected override void OnNavigatedTo(NavigationEventArgs e)
    {
        //Recent.ItemsSource = App.PictureList.Pictures;  //working, unsorted

        Source = new System.Windows.Data.CollectionViewSource();
        Source.Source = App.PictureList.Pictures; //Not Working
        //Need some sort of Cast to IList for LongListSelector?
        Recent.ItemsSource = Source.View as IList<??>();

        if (Settings.AscendingSort.Value)
        {
            //Recent.ItemsSource = PictureRepository.Instance.Pictures.OrderBy(x => x.DateTaken);
            //Recent.ItemsSource = App.PictureList.Pictures.OrderBy(x => x.DateTaken);
            Source.SortDescriptions.Clear();
            Source.SortDescriptions.Add(new SortDescription("Date", ListSortDirection.Ascending)); 
        }
        else
        {
            //Recent.ItemsSource = PictureRepository.Instance.Pictures.OrderByDescending(x => x.DateTaken);
            //Recent.ItemsSource = App.PictureList.Pictures.OrderByDescending(x => x.DateTaken);
            Source.SortDescriptions.Clear();
            Source.SortDescriptions.Add(new SortDescription("Date", ListSortDirection.Descending)); 

        }
    }

解决方案

How to Sort a LongListSelector in Windows Phone was the best and most simple solution. Slightly changed my implementation but it works great.

这篇关于如何排序使用CollectionViewSource一个LongListSelector的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！